When the procedure is implemented during flight, the crew performs the required actions by actuating controls positioned in the cockpit, either directly by switches or by computers and software controlled by the crew.
In traditional piloting with a two-person crew, a first member of the crew handles short-term piloting and a second member of the crew successively performs various actions set out in the procedure under the oversight of the first member of the crew for significant or irreversible actions, such as an engine shutoff, fire extinguishment, etc.
The procedures are generally listed in one or more operating manuals of the aircraft, available in paper or electronic form. Many procedures are certified and must be applied strictly by the crew, in particular in case of failures.
In modern airplanes, the procedures are stored in the form of computer files in a database and can be displayed on the screen of the cockpit when they must be implemented.
Generally, the actions to be performed are displayed successively on a display, the crew having to validate the performed actions as they are carried out.
Some procedures are complex by nature and comprise several alternative sequences resulting from separate series of steps based on choices to be made by the crew, or airplane system statuses.
In this case, the user may have difficulties following the procedure and/or clearly assessing the stage of the procedure he is in.
Known viewing systems make it possible to successively display all of the steps of the procedure, but are complex to comprehend, in light of the small size of the display on which the procedure is displayed in the cockpit.
To that end, the different actions of the procedure are displayed one after the next. On a small display, in the case of one alternative among several series of steps, the user must first descend through the procedure to view all of the actions to be performed in a first series of steps, before reaching the actions to be performed for the second series of steps. This may cause him to lose time and be detrimental to his understanding of the procedure.